PTSD can happen in children, and there is a post further down discussing delayed PTSD. Sometimes one dissociates for as long as necessary. Perhaps this is what she was doing, or possibly still is. Can you enlist the help of a psychologist specialising in children? Or is there anyone close to her that she will open up to? Maybe her teacher?
Does she still see her father? I take it, that your dad was her "father figure"?

Trippin - you're going through a lot right now, and I pray for strength for you to get through this. Don't walk this path alone - there are people out there, and we all care for you.